Segment Reporting (Summary Of The Operating Information) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Segment Reporting Information [Line Items]
Revenue	$ 1,276,007	$ 1,184,557	$ 3,828,487	$ 3,538,654
Cost of revenues	202,904	182,970	624,960	564,119
Operating expenses	825,197	759,362	2,462,107	2,275,550
Total costs and expenses	1,028,101	942,332	3,087,067	2,839,669
Operating earnings (loss)	247,906	242,225	741,420	698,985
Domestic Segment
Segment Reporting Information [Line Items]
Revenue	1,133,971	1,055,037	3,421,429	3,132,566
Cost of revenues	176,198	161,625	549,895	488,404
Operating expenses	502,256	446,704	1,474,591	1,304,731
Total costs and expenses	678,454	608,329	2,024,486	1,793,135
Operating earnings (loss)	455,517	446,708	1,396,943	1,339,431
Global Segment
Segment Reporting Information [Line Items]
Revenue	142,036	129,520	407,058	406,088
Cost of revenues	26,706	21,345	75,065	75,715
Operating expenses	68,229	60,430	197,333	183,824
Total costs and expenses	94,935	81,775	272,398	259,539
Operating earnings (loss)	47,101	47,745	134,660	146,549
Other
Segment Reporting Information [Line Items]
Operating expenses	254,712	252,228	790,183	786,995
Total costs and expenses	254,712	252,228	790,183	786,995
Operating earnings (loss)	$ (254,712)	$ (252,228)	$ (790,183)	$ (786,995)